The lateral geniculate nucleus (LGN) in the thalamus is a structure critical for processing visual information from the retina and sending this information to the visual cortex. Our understanding of the primate LGN has grown since the seminal work of Drs. David Hubel and Torsten Wiesel in the 1960s, but some significant gaps in knowledge still exist. First, mechanisms of nonlinear response gain modulation in parvocellular cell layers are poorly understood. Second, there exists only limited knowledge of the fine anatomical structure of functional cell types. Recent advances in visual stimulus presentation and extracellular recording technology will be utilized to address these gaps in knowledge. The research performed here will test the hypotheses that parvocellular neurons have nonlinear gain modulation and that functional cell types are clustered within LGN laminae. The results will have broad impacts on our understanding of information processing in the early visual system.